Method for preparing biodiesel by biological-chemical catalytic coupling

Abstract

The invention provides a method for preparing biodiesel by biological-chemical catalytic coupling. Fatty acid or biolipid, such as plant oil, animal oil, waste cooking oil and the like is used as raw materials for biological catalysis reaction with lipase as catalyst in a stirred or fixed reactor, is balanced for chemical catalysis reaction with sulfuric acid or solid acid as catalyst to finally obtain reaction liquid containing 97% to 99% of fatty acid methyl ester, and is separated to obtain the biodiesel product. The technique disclosed by the invention is a environment-friendly biodiesel production technique; compared with the original biodiesel production technique, the biological-chemical catalytic coupling preparation technique originated by the invention has the features of wide raw material adaptation range, convenience for process operation, low raw material consumption, high product conversion rate, low production cost, strong environmental friendliness and the like.

Description

Technical field [0001] The invention relates to biochemical industry, in particular to a method for synthesizing short-chain fatty acid short-chain alcohol esters, namely biodiesel, by catalyzing the reaction of fats and short-chain alcohols under solvent-free or solvent-free systems by combining biological and chemical catalysis methods. Background technique [0002] Biodiesel is a form of biomass energy, the main component of which is fatty acid methyl ester. It is made from renewable resources such as oil crops such as soybeans and rapeseeds, oil palm and pistacia tree fruits, engineering microalgae and other oily aquatic plants, animal fats, waste catering oil, etc. It is similar to petroleum diesel Performance. At the same time, biodiesel has the advantages of low sulfur content, low aromatic content, excellent lubricity, renewable, and environmental friendliness, and has attracted much attention. [0003] As raw materials for synthetic biodiesel (vegetable oils and animal f...

AI Technical Summary

Problems solved by technology

However, chemical synthesis of biodiesel has the following disadvantages: the process is complicated, alcohol must be excessive, and a corresponding alcohol recovery device must be installed in the follow-up, which requires high energy consumption; the color is deep, because the unsaturated fatty acids in the fat are easy to deteriorate at high temperatures; the production process has spent alkali liquid discharge

The following problems were also found in the enzymatic synthesis research: (1) lipase aggregates in lipophilic organic solvents, which affects the catalytic efficiency; (2) the short-chain alcohol used in the reaction has a great impact on lipase. Toxicity; (3) The by-product glycerol has side effects on the transesterification reaction system

However, the process of acid first and then alkali also has the following disadvantages: the equipment must be resistant to strong acid; a large amount of waste water is generated after the reaction, and the catalyst cannot be reused; side reactions are likely to occur with concentrated sulfuric acid catalysis, which affects product quality.